Hey everyone!  

I've had these parts for weeks but I've been putting off this build to deal with some personal stuff lately.  I finally felt up to it, so it's time for another build post!


First of all I want to point out a few things about this Catalyst Machine Works: Shocker frame.

1.) It is not as hard of a build as it looks, but I would NOT recommend this frame for a first-time builder.    The number of small components of the frame build, combined with the fact you will most likely need to re-map the motors and flip orientation of the FC makes this an unsuitable build for a first-timer.  For experienced people remapping motors and flipping board orientation takes only a few minutes but for those just getting into BetaFlight for the first time, that is asking for headaches.  First-time builders should stick with a 'standard' 5" Freestyle frame with tons of room and no need to build it upside-down or remap motors.

2.) I differed from the CMW standard build instructions in a small way due to a disagreement I have with one of CMW's 'design choices'. (read: shortcut they took)

Despite charging $550 USD for their pre-built, they attach the Vista vTx unit to the quad with nothing but a piece of double-sided tape. And encourage you to do the same in their build instruction video.

Seriously?
All this effort to build the frame, and they want you to attach the single heaviest, hottest, and most expensive component to the quad with nothing but double-sided tape to a piece of TPU that is held to the frame with tiny self-tapping screws?!  WHY?  I will use double-sided tape to hold in a nano RX, but a Vista? that just didn't sit right with me.
The frame already has m2 20x20 holes cut in it, and the Vista already has the m2 20x20 holes.  So why not just use them and secure it right? Even if you want to use that rear LiPo strap you can just put spacers in between the frame and vista and still use m2 bolts and nuts to hold it on correctly.  
Mounting the Vista how I have done it with bolts also ensures air-flow on that top heat-sink rather than it being covered by double-sided tape.

Anyway... On to the build:

Components:
Frame:  Shocker 4" Frame
Motors:  BH TC 2004 3150kv
STACK:  Diatone Mamba F722 w/ 40a 32bit 4n1 ESC
vTx:  Cadx Vista with original DJI camera
Rx:  CrossFire Nano


Build Pics:










Vista mounted with bolts+nuts rather than stick-tape:















Dry weight with strap + battery pad + props : 205.8g



AUW ready to fly: 310g  (fine with me, as I obviously wasn't trying to make 250g)



With my current digital line-up by size: 3" GepRC Phantom, 3.5" Avant Avio, 4" CMW Shocker, 4.8" GepRC Mark4 (fits up to 5.1", but I run 4.8") Can you tell I like HQ props?





Maiden flight will probably be tomorrow morning, so I can't speak on how it flies just yet.

Nice build. I love the look of those pointy back bits on the rear of the frame.

Definitely agree with your opinion on the Vista mounting.

They should have included the belly skids and arm bumpers as part of the kit. On most Merica frames we do not even get the canopy.

CMW kits usually do not include printed parts unless its vital for the frame structure. I am also surprised they do not provide STL's for us to print our own as several other frame designers do. If you are lucky you find some on thingiverse.

Another feature missing on these frames is a precut lipo pad. I know many just stick ummagrip or something similar but its a pain to get the cuts looking right.

Looking for to your flight experience on the frame.

Looks good, I've enjoyed mine and recently picked up the tpu for the bottom like I have on the Shocker Tank. Though like the Tank when I land it with the way the bottom is curved makes it roll over forward on it self when you bring it in a little hot for a landing. I did add some 20mm standoffs like the large Shocker comes with which is mainly for the action cam TPU mounts. 

I just need to fly it more, I'm too immersed in the 6s 5" quads at the moment. I took it out yesterday but I was in a cramped space that I was unfamiliar with so I didn't really get to send it. This thing hauls ass compared to the 5" quads I have, you can even see it when watching on the DVR, the playback looks like one of my 5" quads at x1.25 speed. 






Never did bother to source a more reasonable sized cap than the one the stack came with. Long gone are the days of ordering capacitors in bulk from Mouser.

I didn't order the belly skids yet but I think I might get them. Can you use just the middle part, or do you need to install all 3 pieces? I want it just for when I land in grass I don't have damp grass pressing up on the flight controller.

I think I will add on the standoffs over the cam like you have just for some extra strength.

(07-Dec-2021, 12:34 AM)kafie1980 Wrote: Definitely agree with your opinion on the Vista mounting.

They should have included the belly skids and arm bumpers as part of the kit. On most Merica frames we do not even get the canopy.

CMW kits usually do not include printed parts unless its vital for the frame structure. I am also surprised they do not provide STL's for us to print our own as several other frame designers do. If you are lucky you find some on thingiverse.

Another feature missing on these frames is a precut lipo pad. I know many just stick ummagrip or something similar but its a pain to get the cuts looking right.

Looking for to your flight experience on the frame.

I even had to pay a little extra for the immortal-T TPU mount on the back. For the battery pad I just use a square of 3M stick on material that grips lipos well.

(07-Dec-2021, 01:50 AM)MrSolo Wrote: I didn't order the belly skids yet but I think I might get them.  Can you use just the middle part, or do you need to install all 3 pieces?  I want it just for when I land in grass I don't have damp grass pressing up on the flight controller.

I think I will add on the standoffs over the cam like you have just for some extra strength.

Yes it should work with just the middle.

I just got back from the maiden flight. Albeit a very brief one, as I forgot to turn on my OSD element for Batt Voltage, so I had no idea where my battery level was at. I have a Speedy-Bee for field work, but it is Micro-USB and this FC is USB-C, so I stuck to 2 min flights to be safe.

Also Sevro - I see what you mean about the round bottom making it want to roll forward on landings unless you are very gentle. I flipped it over forwards on 2 out of 4 landings this morning.

It also definitely needs some tuning from the stock settings. It is getting quite a bit of prop-wash, and when I suddenly chop the throttle it does a bad wobble. That should be sorted out with the sliders easily enough. I will probably just move the sliders more in line with UAVTech's presets and I bet it will be spot on. The only thing I changed before this morning's flight was Props-Out and Bi-Directional DSHOT.

But apart of that it flew great, and it is fast.

(07-Dec-2021, 06:00 PM)MrSolo Wrote: Also Sevro - I see what you mean about the round bottom making it want to roll forward on landings unless you are very gentle.  I flipped it over forwards on 2 out of 4 landings this morning.

It's like landing a boat.

I got to fly it again for the 2nd time this morning. I moved the sliders close to UAVTech's presets for a 5" freestyle quad and now it flies amazing! No more prop-wash or wobble when I cut the throttle.

And DAMN is it fast. I'm not sure which is faster between my Avio 3.5 or the Shocker 4, but they both haul ass! I'll have to get more used to the Shocker and maybe time myself around a course at the park or something.

I've also gotten better at gentle landings; didn't flip it over once this morning.

So far I would definitely recommend this quad to anyone that wants something lighter and quieter than a 5", but still gets your heart pumping. It's a harder build than your average 5", but for someone that has built a quad before I would give this 4" Shocker '2 Thumbs up!'


The only problem I notice now is that my batteries didn't seem to last very long this morning. I'm not sure if it was because it was kind of cold, or maybe the RDQ LiPos just aren't the best. Or maybe because it is a new quad I haven't learned the best throttle control on it yet. Or perhaps a mixture of all 3. But I don't think that is a quad issue.

Overall the Shocker has not disappointed me, and I would recommend it for anyone looking for something a little less than a 5", but more than a micro. As said though, it is fast! So if you are unsure of yourself on the sticks I would use a very low camera angle.

Looks good.
 Every time I see a shocker I always want one.
 They just look good  sitting idle.

Hi MrSolo,

First, very nice build. Good Job. 

I like your fleet. SWEET  

Now, I am curious.     

Did you actually have to re-map the motors and flip the FC orientation. 

If so, why did you need to do that. 

I have "bottom" mounted electronics and didn't have to do anything to the FC orientation
nor any motor re-mapping. Things just mount in reverse order keeping the standard orientation.
At least that is the way that I did it.

Yes I remapped my motors and added 180 Roll to the FC.

It could be done without it, but then the build would be more difficult.

The choice is either build it the easy way with the ESC and FC facing the normal orientation while building (which would then be upside down while flying), or flip the ESC upside down while building it which would make the soldering harder as you could then only solder to the sides of the board, not the tops of the pads.

Then same for the FC, I could have just soldered the RX to the pads on top and then flipped the FC over with a twist in the harness between FC and ESC and not had to do the 180- board orientation.

But if I did it that way maintenance in the future would have been more difficult. By simply remapping the motors left-to-right and adding 180 roll orientation, I was able to build with the stack and solder pads facing the right way up. It adds a few minutes to the software side of things, but it makes building easier, and also makes maintenance easier in the future because I can clearly see the pads on the FC without having to look in between the boards or the stack and frame.

It comes down to personal preference I suppose. It could be built either way. I just felt it was easier to build with the stack upright for easier build and future maintenance, and then add the 180 roll and motor remap because the stack is then upside down once you flip the quad over to its flying orientation.

Dude that is one sick fleet and a sick build. And not gonna lie, that is one slick frame!

Hi MrSolo,

Thanks for explaining your perspective on building a quad with underslung electronics.

I guess that I just have not yet seen any situation where I couldn't mount the FC in
the orientation that it was intended. 

It is no problem for me since I assemble the electronics package before mounting the system
into the frame. The entire electronic package is soldered up on the bench. Plus, I generally
use connectors for the components including the motors. Also, I mostly use AIO boards rather 
than stacks particularly the 26x26 diagonally oriented whoop FC boards. Once the electronics
package is together, I install it into the frame. Actually, I can install it into any frame or even
move the entire system from one frame to another.

Here is one of my typical electronics packages. This is a standard setup including the connectors.

Here is a picture of one of my systems with the motors soldered directly to the FC {which is rare for me}.

Since I don't do soldering on the FC when it is mounted in the frame, it doesn't matter whether
the electronics are on top of the bottom plate or mounted in an underslung manner. Placing the
FC in the proper orientation is no problem.